Pred-Ex: Long Term Salt Marsh Predator Exclusion Experiment Conducted at Sapelo Island, GA

In southeastern USA salt marshes, short-term and small-scale experiments indicate that a trophic cascade benefits the foundation plant Spartina alterniflora: marine predators (nekton) positively affect plant biomass by consuming snail and crab herbivores. To test how nekton affect marsh processes when the entire animal community is present, and to test how prior results scale up over time, we conducted a 3-year predator exclusion experiment in a Georgia salt marsh using replicated 19.6 m2 plots. We measured the response of changing density for all marsh invertebrates, conducted snail and crab tethering trials, quantified change in marsh grass biomass, and measured tea bag decomposition rate across all plots.